fix:fix config startup load cache retry bug. (#609)

Author: SkyeBeFreeman

polaris-configuration/polaris-configuration-client/src/main/java/com/tencent/polaris/configuration/client/internal/ConfigFilePersistentHandler.java

@@ -206,24 +206,32 @@ private Path doSaveConfigFile(ConfigFile configFile) {
      * @param configFile 配置文件
      * @return 配置文件
      */
-    public ConfigFile loadPersistedConfigFile(ConfigFile configFile) {
+    public ConfigFile loadPersistedConfigFile(ConfigFile configFile, boolean needRetry) {
         String fileName = configFileToFileName(configFile);
         String persistFilePathStr = persistDirPath + File.separator + fileName;
         Path persistPath = FileSystems.getDefault().getPath(persistFilePathStr);
-        int retryTimes = 0;
         ConfigFile resConfigFile = null;
-        while (retryTimes <= maxReadRetry) {
-            retryTimes++;
+        if (needRetry) {
+            int retryTimes = 0;
+            while (retryTimes <= maxReadRetry) {
+                retryTimes++;
+                resConfigFile = loadConfigFile(persistPath.toFile(), configFile);
+                if (null == resConfigFile) {
+                    Utils.sleepUninterrupted(retryInterval);
+                    continue;
+                }
+                break;
+            }
+            if (null == resConfigFile) {
+                LOG.debug("fail to read config file from {} after retry {} times", fileName, retryTimes);
+                return null;
+            }
+        } else {
             resConfigFile = loadConfigFile(persistPath.toFile(), configFile);
             if (null == resConfigFile) {
-                Utils.sleepUninterrupted(retryInterval);
-                continue;
+                LOG.debug("fail to read config file from {}.", fileName);
+                return null;
             }
-            break;
-        }
-        if (null == resConfigFile) {
-            LOG.debug("fail to read config file from {} after retry {} times", fileName, retryTimes);
-            return null;
         }
         return resConfigFile;
     }

polaris-configuration/polaris-configuration-client/src/main/java/com/tencent/polaris/configuration/client/internal/RemoteConfigFileRepo.java

@@ -253,7 +253,7 @@ private void fallbackIfNecessary(final int retryTimes, ConfigFile configFileReq)
         if (retryTimes >= PULL_CONFIG_RETRY_TIMES) {
             LOGGER.info("[Config] failed to pull config file from remote.");
             //重试次数超过上限，从本地缓存拉取
-            loadLocalCache(configFileReq);
+            loadLocalCache(configFileReq, true);
         }
     }
 
@@ -268,13 +268,14 @@ private void fallbackIfNecessaryWhenStartingUp(ConfigFile configFileReq) {
         if (!initFlag) {
             // 第一次启动的时候，如果拉取到空配置，则尝试从缓存中获取
             LOGGER.info("[Config] load local cache because of empty config when starting up.");
-            loadLocalCache(configFileReq);
+            // 不需要重试
+            loadLocalCache(configFileReq, false);
         }
     }
 
-    private void loadLocalCache(ConfigFile configFileReq) {
+    private void loadLocalCache(ConfigFile configFileReq, boolean needRetry) {
         if (fallbackToLocalCache) {
-            ConfigFile configFileRes = configFilePersistHandler.loadPersistedConfigFile(configFileReq);
+            ConfigFile configFileRes = configFilePersistHandler.loadPersistedConfigFile(configFileReq, needRetry);
             if (configFileRes != null) {
                 LOGGER.info("[Config] load local cache success.{}.", configFileRes);
                 remoteConfigFile.set(configFileRes);